The >10MB size of the static executable is kind of getting out of hand especially on embedded systems with very limited RAM. Using shared libs means many concurrent instances of FFmpeg can use broadly the same memory footprint, and package distribution binaries can be smaller – our target systems already have libmp3lame, libm, libz, libbz2, liblzma, libpng16, librt, libgmp, libgnutls, libhogweed, libnettle, libfreetype, libfontconfig, libexpat, and libpthread which add up to several megabytes. I’m also guessing that the OS will decide when to unload them from RAM which could help when FFmpeg is being launched repeatedly in a short period of time (e.g. during library scanning).

The notes below also detail how to compile the Synology fork of FFmpeg 2.7.1 with Intel Evansport SMD (Streaming Media Drivers) hardware transcoding support. This source is itself based upon a fork by Intel which seems to form part of the Evansport SDK. Synology took a very long time (over a year) to partly comply with the GNU Public License and release this source code, despite numerous support requests, forum posts, and reports to the GPL Violations team. Their first DSM 6.0 beta was released in October 2015, and the DSM 6.0 sources were only published in late November 2016, but these remain incomplete since the kernel sources are not included.

Although the unmodified FFmpeg source code will compile successfully for PowerPC CPUs, the FFmpeg binary will core dump when running any command on a video file. I contacted Synology Support for help with this issue back in October 2012 and was given a patch to use at that time which changes the use of a CPU register in the DSP assembly code. The FFmpeg source code has changed a bit recently meaning the patch was no longer valid, but I was able to discover the appropriate location in the code and create a new working patch (code was moved from dsputil_ppc.c to blockdsp.c):

Here’s how the library dependencies look. There are no links to any libraries in /opt, and DSM-bundled libraries in /lib are linked to where possible. All the other new libraries are kept within the Serviio lib folder (../lib relative to the ffmpeg binary).

This method will build FFmpeg 2.7.1 with the shared libraries (linked with relative paths) required for Serviio DLNA media server, using a Ubuntu/Xubuntu Desktop 14.04 virtual machine, however the same method probably works with many other Linux distributions. The target CPU architectures are ARMv5, ARMv7, ARM hard float ABI with NEON, Intel i686, Intel x64, and PowerPC e500v2.

The >10MB size of the static executable is kind of getting out of hand especially on embedded systems with very limited RAM. Using shared libs means many concurrent instances of FFmpeg can use broadly the same memory footprint, and package distribution binaries can be smaller – our target systems already have libmp3lame, libm, libz, librt, libgmp, libssl, libcrypto, libfreetype, libexpat, and libpthread which add up to several megabytes. I’m also guessing that the OS will decide when to unload them from RAM which could help when FFmpeg is being launched repeatedly in a short period of time (e.g. during library scanning).

The notes below also detail how to compile the Synology fork of FFmpeg 2.0.2 with Intel Evansport SMD (Streaming Media Drivers) hardware transcoding support. This source is itself based upon a fork by Intel which seems to form part of the Evansport SDK. It was not straightforward to compile, and now that I have released Serviio for Synology with hardware transcoding support I’m sharing my method in the hope it can help others. This older FFmpeg needs a patch to fix a long standing bug with DTS audio remuxing (reported by me) where the stream ID was incorrectly set:

Although the unmodified FFmpeg source code will compile successfully for PowerPC CPUs, the FFmpeg binary will core dump when running any command on a video file. I contacted Synology Support for help with this issue back in October 2012 and was given a patch to use at that time which changes the use of a CPU register in the DSP assembly code. The FFmpeg source code has changed a bit recently meaning the patch was no longer valid, but I was able to discover the appropriate location in the code and create a new working patch (code was moved from dsputil_ppc.c to blockdsp.c):

Here’s how the library dependencies look. There are no links to any libraries in /opt, and DSM-bundled libraries in /lib are linked to where possible. All the other new libraries are kept within the Serviio lib folder (../lib relative to the ffmpeg binary).